Just another case of Leftists assaulting other Leftists. Their rage is so out-of-control, they are so rabid with HATE that they attack and physically assault anyone, anyone at all, who they perceive to be not in agreement with their way of thinking. Their were many in the "protesters" injured by the crowd by mistake. They were assaulted just because one or more people in the crowd thought that they were secretly not, or not enough, onboard with the program. This determination is made not by facts or reason, but by their own singular personal perception.
Leftists are dangerous people, even to their own. It is like joining the KKK or the Mafia. As long as you stay inline you should be safe. But if you step a single foot out of bounds, then you are in for their fury.